diphenoxylate and atropine, Lomotil

Omudhome Ogbru, PharmD

Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

GENERIC NAME: diphenoxylate and atropine

BRAND NAME: Lomotil

DRUG CLASS AND MECHANISM: Lomotil is a combination of two drugs, diphenoxylate and atropine. It is used to treat acute diarrhea (diarrhea of
limited duration). Diphenoxylate is a man-made narcotic chemically related to
meperidine (Demerol). Like other narcotics, diphenoxylate reduces diarrhea by
interfering with the propulsion of intestinal contents through the intestines.
Although diphenoxylate is chemically related to narcotics, it does not have
pain- relieving (analgesic) actions like most other narcotics. In higher doses,
however, like other narcotics, diphenoxylate can cause euphoria (elevation of
mood) and physical dependence. In order to prevent abuse of diphenoxylate for
its mood-elevating effects, atropine is combined with diphenoxylate in small
quantities. As a result, if Lomotil is taken in greater than recommended doses
unpleasant side effects from too much atropine will occur. Lomotil was approved
by the FDA in 1960.

DOSING: In adults, the usual dose is 5 mg (2 tablets) of diphenoxylate
three to four times per day initially. Thereafter, the dose may be decreased to
2.5 mg (1 tablet) two to three times a day. The dose for children (2 to 12 years
old) is 0.3 to 0.4 mg/kg/day in four divided doses. If diarrhea is not better
within 48 hours, diphenoxylate is not likely to be effective with more prolonged
treatment.